57. CONTRIBUTION TO 



BORDENIA, N. Gen. 



(Ety proper name.) 



Corallum simple or composite, resembling Zaphrentis. Tabulae complete 

 with the central portion being smooth. Fossette well pronounced or scarcely- 

 more than rudimentary. Primary lamellae well defined. Secondary lamellae 

 rudimentary or indicated by fine stria3. Type B. Zaphrentiformis. 



BORDENIA, ZAPHRENTIFORMIS. N. Sp. 



Plate 19. Figs. 2-9. 



Corallum simple or composite, turbinate, or sub-cylindrical, slightly curved, 

 usually having a broad ecar at the base of attachment, and some examples 

 have root-like prolongations that served for attachment and support. Slightly 

 enlarging in diameter to the calix. Height from ten to forty millimeters, va- 

 rying in diiferent individuals. Calix oblique, somewhat campanulate, from 

 ten to twenty millimeters in diameter. Depth from three to ten millimeters, 

 with vertical walls. In the bottom of the calix there is a flat oblique space oc- 

 cupied by the tabuhe. occupying the entire diameter of the corallum at that 

 point. Number of lamellae, fifty-two, in the circumference of a calix, fifteen 

 millimeters in diameter, the short ones scarcely more than rudimentary ; the 

 longer ones are sharp, slightly elevated, rapidly descend to the bottom 

 of the calix, and extend a short distance on the tabulae, and gradually 

 disappear, leaving a smooth, oblique space in the bottom of the calix, from five 

 to six millimeters in diameter. This feature is only in corrallums that have no 

 buds; when there is buds the number of lamelhe cannot be made out. The ex- 

 terior appears somewhat rugged, from the strong oblique wrinkles, and con- 

 strictions. The fossette is not well defined: it consists of a small depression on 

 the side of the tabulae, more strongly pronounced on the reversed side. 



This coral has has been labelled Amplexus Coralloides (Sowerby) Mineral 

 Conchology ; by many collectors. Mr. Sowerby supposed his speciman was a 

 cephalopod shell and described it as such. If the genus Amplexus should be 

 applied to corals, this coral would not be placed in that genus. 



Mr. G. B. Sowerby, Jr., in Conchological Manual, second edition, 1842, 

 page 64, says that Amplexus, a generic name proposed by Captain Brown for 

 Helix Pulchella. Drop. 112, Tab. 107, page 134. 



Found in the Warsaw division of the St. Louis group (sub-carb.) in Harri- 

 son, Floyd and Washington counties, Indiana. Now in the collection of the 

 author. 



